This study evaluates the hypothesis that enteral feeding with glutamine-enriched dietary formula will attenuate the alteration in lymphocyte function, interleukin-1 production, and intestinal permeability caused by the acquired immunodeficiency syndrome. Parameters of lymphocyte function, interleukin-1 production, and intestinal permeability will be evaluated in patients with AIDS, fed a standard formula diet versus a glutamine-enriched formula diet in a prospective randomized crossover study.